Top for blast-furnaces



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]E. B. RICHARDS.

Y Tor Pon BLAST PURNAGES. if NO. 532,584. PatentedJaJn. 15, 1895.

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FRANKLIN B. RICHARDS, OF CLEVELAND, OHIO.

TOP FOR BLAST-FURNAcl-:s-

SPECIFICATION forming part of Letters Patent No. 532,584,` dated January 15, 1 895.

Application led July 24, 1894- I Serial No. .518,477- (No model.)

To all whom it may concern.-

Be it known that I, FRANKLIN B. RICHARDS, a citizen ofthe United States, residing at Cleveland, inthe county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Tops for Blast-Furnaces; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art 'to which it appertains to make and use the same. y

My invention has reference to tops for blast furnaces, and the object of the invention is to provide a furnace which isA especially adapted to handle certain kinds or grades of ores in which there is an unusual quantity of very line ore and which with the old style of l furnace was carried over with the gas from the top of the furnace through the down comer iues into the stoves, or deposited in the main gas fiues under the boilers, or in fact wherever the waste gases were utilized for heating. Again, these tine ores would accumulate or hang on the lower bosh Walls of the furnace to such extent that they would cause numerous and terrible explosions in the furnacetops when released suddenly, often throwing out` the bell and the charging hopper and injuring and in' some cases killing the top men who fill the furnace with stock. The present i11-` vention is designed to overcome and avert these dangers, and to provide a furnace top in which the fine or .powdered ore is kept mostly from entering the down comer flues and to avert the dangers from explosions that have become frequent of late in furnace opq erations, all substantially as shown and described and particularly pointed out inthe claim.

In the accompanying drawings, Figure 1 is a side elevation partly in section, of a furnace top constructed and operating according to my improvements, the section lines being on line 1 and 1, Fig. 2. Fig. 2 is a cross-section of the' furnace top on a line corresponding substantially to 2, 2, Fig. l. Fig. 3 is an enlarged vertical section of one of the explosion doors and the outer rim or casing carrying said doors. ff

One embodiment of the invention, as shown in the drawings forming a part of this specification, comprises' a combined expansio'n chamber or space and draft flue about the top of the furnace A and. outsideI or mostly outsideof theline of the main wall thereof, and formed by and between the inclined bottom 2, the top wall or covering -3- and the outside wall -thaving openings at intervals covered or closed by doors E.- These walls are of suitable brick work and the Weight thereof is largely orr mainly sustained by thek bracket -7-, or their equivalent,v occupying the angle between the bottom of said chamber andthe main wall of the furnace A. The said expan- ,sion chamber and flue is connected with the inside ofthe extreme top of the furnace A by a number of up-take flues or passages equidistant'from each other around the circle of the top and separated from each other by the walls -8-.. These walls and tlues come directly beneath the charging hopper -9- and there may be as many of said iiues as the construction ot brick work will admit. These flues and the door of the expansion chamber should be at quite a steep inclination as will be explained farther on.

With the expansion chamber or fiue are connected the down comer flues D, one or more, whereby the gases which gather about the top of the furnace are carried beneath to the stoves and consumed. These down comer flues are the regular and ordinary channel or passage-way for gasesjwhch drift into the expansion chamber, and all other means of egress for such gases should be closed. I have provided the said chamber with aseries of doors E about its outside. These doors are known to me as explosion doors, because they are designed to open only when explosions in the top of the furnace occur and to be closely shut at all other times. Said doors are preferably made of cast iron and hinged at their top to swing outward.4 However, a bottom hinge may be used it' desired, or, iudeed, a side hinge. They are shown here as hinged to an outside shell, casing or rim F of iron, and cover each a port or opening l0- extending through the brickA work or outer wall of the expansion chamber. As many of these doors are used as space-and safety of brick work construction will allow, and in any event the combined area of the said doors should equal the bell opening of the roo aord a large overlapping surface, and that there is a channel or groove -12- all around in the oiset or flange 13- of the ring which may be filled with damp clay or any equivalent material against or upon which the door will close and prevent leakage of gas. The door itself has an inside lining -14- of asbestos to resist heat and corrosion. However, if for any cause whatever,the door should leak after taking the precautions already described, I

' may supplement the construction with the flange or offset -16 on the ring or casing F close to the edge of the door at the bottom and sides and lute the crack about the door with clay, and another olset or flange -l7 may be placed on the door itself across its top for luting in like way.

When the furnace is in operation it is filled with stock up to within two or three feet of the bottom of the uptake flues. The heated air is forced in at the bottom of furnace by blowers at a pressure varying according to conditions from five and one-half to fourteen pounds to the square inch. The air passing through the coke of the charge is converted into gas which comes in a large volume to the top of the furnace, where the pressure is very much reduced as a matter of course. In the form of top as here shown the dilusion ofthe gases would be nearly equal in all directions up through the up-take iiues into the expansion flue where the tensity of the gas would be relieved by the chance to expand, and the very fine particles of ue dust (composed mostly of fine ore and fuel) would settle largely in the inclined floors of the expansion flue and up-take dues, and, being hot, would readily iow back into the furnace. It is not expected that this separation would becomplete or perfect, but it would materially aid the dust catchers and prevent a material loss of fine ore sweeping out with the gases as heretofore. In the event of an explosion the expansion flue would take up for an instant, by compression, the first shock of the explosion, and give the explosion doors a chance to act uniformly and relieve the pressure at once, thus saving the wrecking of bell and hopper and other parts of the usual top hamper as well as avoiding such violence of action as would endanger life.

In Fig. 1 a pipe-like chimney or stack G is shown at the top and bend of the down comer flue D. This stack is shown with an automatically closing cover or valve H on its top, and serves merely to relieve possible excess of pressure in said pipe. It is however old and well known in the art and forms no part of this invention.

Having thus described my invention, what I claim is The furnace described having an annular chamber about its top provided with inlet ports about its inside and outlet ports about its outside and the bottom of said chamber and its ports having a common inward and downward inclination, self-closing doors for the outlet ports and down comerflues leading from said chamber, substantially as set forth.

Witness my hand to the foregoing specification this 5th day of July, 1894.

FRANKLIN B. RICHARDS.

Witnesses:

H. T. FISHER, GEORGIA SCHAEFFER. 

